The present invention relates generally to the field of surgical instruments, particularly instruments employed in ophthalmologic surgical procedures. In preferred forms, the present invention relates to miniaturized surgical instruments which are especially well suited for ophthalmologic surgical procedures, for example, to aid the surgeon during macular translocation.
Macular translocation for the treatment of macular degeneration has recently attracted attention as a means to treat age-related macular degeneration. In this regard, and in numerous intraocular surgeries, it is necessary for the surgeon to complete different surgical maneuvers inside the eye such as, stopping bleeding, irrigating or aspirating blood or other fluids or injecting fluid through a retinotomy and using suction to hold tissue to be moved within the eye and fluid flow to release the suction to the tissue. Removing and replacing an intraocular instrument during these maneuvers increases the risk of complications such as retinal tearing or incarceration of detached retina or may allow outflow of fluid during instrument exchange thus increasing the risk of continuation of bleeding. Thus, it is preferred to have an instrument that can perform multiple maneuvers that may be required in sequence.
Therefore, it would be highly desirable if instruments were available that would allow the surgeon to easily and without damage, perform a series of surgical functions, such as, for example, compress bleeding blood vessels while viewing the source of bleeding and extent of tissue blanching from compression, irrigate or aspirate away blood to assist in finding the source of bleeding, irrigate fluid through a hole in the retina while obstructing backflow to create separation of the retina from underlying tissue, securely hold onto retinal or other tissue during attempts to move or otherwise relocate the tissue and then readily release the tissue. It is towards fulfilling such a need that the present invention is directed.
Broadly, the present invention is embodied in surgical instruments having a smooth, bulbous arcuate tip which surrounds a distal end of a lumen. The relative positioning of the lumen and the arcuate tip allow a surgeon to perform a series of surgical functions, such as those identified above. The rounded ball form of the tip associated with the surgical instruments of the present invention prevents abrasion or gouging of adjacent structures as can occur with a typical xe2x80x9csquared offxe2x80x9d cannula. Most preferably, the tip is formed of a compliant, yet self-supporting, material, such as medical grade transparent silicone elastomer.
The bulbous arcuate tip may take various geometric forms. In this regard, the external surface of the tip is arcuate and thus may be generally spherical, ellipsoid or the like. Also, the bulbous arcuate tip may be symmetrical about the elongate axis of the instrument or may be asymmetrical (i.e., angularly disposed) relative to such longitudinal axis.
The surgical instruments of this invention are most preferably made by first adhering a length of compliant tubing (e.g., silicone) into a distal end of a rigid tube (e.g., a section of a stainless steel needle). Specifically, it is preferred that the proximal rigid tube section is coaxially sleeved over, and affixed to, the distal compliant tube section. A forming wire may then be inserted into the aligned lumens of the proximal rigid tube and distal compliant tube sections so that a terminal end section of the forming wire extends beyond the distal end of the compliant tube section. A bolus of curable liquid elastomer is then applied onto the distal end of compliant tube section around the forming wire protruding therefrom. By rotating or molding and otherwise manipulating the tube sections during curing of the liquid elastomer, a bulbous arcuate tip may be formed. Once the elastomer tip is cured, the forming wire or mold may be withdrawn thereby forming a small hollow bore lumen which terminates at the tip. That is, the bulbous arcuate tip will surround the distal end of the thus formed lumen.
These and other aspects and advantages of the present invention will become more clear from the following detailed description of the preferred exemplary embodiments thereof.